AVIF File Format (AV1 Image File Format)
AVIF is the newest major image format, based on the AV1 video codec developed by the Alliance for Open Media (AOMedia). Released in 2019, AVIF offers superior compression compared to both JPG and WebP, producing files that are 50% smaller than JPG and 20% smaller than WebP at equivalent visual quality. The format supports high dynamic range (HDR), wide color gamut, film grain synthesis, and both lossy and lossless compression. AVIF is royalty-free, which encourages broad adoption. Browser support has grown rapidly, with Chrome, Firefox, Safari, and Edge all supporting AVIF. While encoding is slower than WebP or JPG, the dramatic file size savings make AVIF the best choice for cutting-edge web performance.
Quick Facts
- Extension: .avif
- MIME Type: image/avif
- Category: image
Advantages
- Best compression ratio of any major image format
- Royalty-free and open standard
- HDR and wide color gamut support
- Both lossy and lossless modes
- Rapidly growing browser support
Disadvantages
- Slow encoding speed compared to JPG or WebP
- Limited support in older software and operating systems
- Some browsers have incomplete AVIF feature support
- Not yet widely accepted by social media platforms
- Limited tool ecosystem compared to established formats
Common Use Cases
- Next-generation web image optimization
- Bandwidth-critical mobile web applications
- HDR photo display on supported devices
- Progressive enhancement for modern browsers
- Large-scale image delivery systems (CDNs)
Technical Details
AVIF uses the AV1 intra-frame encoding mode, applying block-based predictive coding with variable block sizes from 128x128 down to 4x4. It supports 4:2:0, 4:2:2, and 4:4:4 chroma subsampling. The AV1 codec uses multi-reference frame prediction, warped motion, and film grain synthesis to achieve compression superiority. AVIF files use the ISOBMFF container (same as HEIC). The AVIF sequence format supports animated sequences. Encoding complexity is O(n^2) relative to quality, which explains the slower encoding speed compared to simpler codecs.
Frequently Asked Questions about AVIF
Is AVIF better than WebP?
AVIF achieves approximately 20% better compression than WebP and supports HDR and wider color gamuts. WebP encodes faster and has broader tool support. Both are good choices for the web.
Do all browsers support AVIF?
Chrome (85+), Firefox (93+), Safari (16.4+), and Edge (121+) all support AVIF. For older browsers, provide JPG or WebP fallbacks using the <picture> element.
Why does AVIF take long to encode?
The AV1 codec uses complex prediction algorithms that produce excellent compression but require more CPU time. Decoding is fast; it is only encoding that is slow.
Should I switch all my website images to AVIF?
Use AVIF with fallbacks. Serve AVIF to supporting browsers via <picture> and fall back to WebP or JPG for others. This provides the best performance across all visitors.